Give a better error message when we try to print a value of unknown type

[ghc-hetmet.git] / compiler / typecheck / TcRnDriver.lhs

diff --git a/compiler/typecheck/TcRnDriver.lhs b/compiler/typecheck/TcRnDriver.lhs
index e26c50b..07a48ae 100644 (file)
--- a/compiler/typecheck/TcRnDriver.lhs
+++ b/compiler/typecheck/TcRnDriver.lhs
@@ -62,6 +62,7 @@ import CoreSyn
 import ErrUtils
 import Id
 import Var
+import VarSet
 import Module
 import UniqFM
 import Name
@@ -72,7 +73,6 @@ import SrcLoc
 import HscTypes
 import ListSetOps
 import Outputable
-import Breakpoints
 
 #ifdef GHCI
 import Linker
@@ -97,6 +97,9 @@ import Util
 import Bag
 
 import Control.Monad    ( unless )
+import Data.Maybe      ( isJust )
+import Foreign.Ptr      ( Ptr )
+
 \end{code}
 
 
@@ -318,7 +321,7 @@ tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
                                mg_deprecs   = NoDeprecs,
                                mg_foreign   = NoStubs,
                                mg_hpc_info  = noHpcInfo,
-                                mg_dbg_sites = noDbgSites
+                                mg_modBreaks = emptyModBreaks  
                    } } ;
 
    tcCoreDump mod_guts ;
@@ -821,10 +824,20 @@ setInteractiveContext hsc_env icxt thing_inside
     in
     updGblEnv (\env -> env { 
        tcg_rdr_env  = ic_rn_gbl_env icxt,
-       tcg_type_env = ic_type_env   icxt,
        tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
 
-    updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
+
+    tcExtendIdEnv (typeEnvIds (ic_type_env icxt)) $
+        -- tcExtendIdEnv does lots: 
+        --   - it extends the local type env (tcl_env) with the given Ids,
+        --   - it extends the local rdr env (tcl_rdr) with the Names from 
+        --     the given Ids
+        --   - it adds the free tyvars of the Ids to the tcl_tyvars
+        --     set.
+        --
+        -- We should have no Ids with the same name in the
+        -- ic_type_env, otherwise we'll end up with shadowing in the
+        -- tcl_rdr, and it's random which one will be in scope.
 
     do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
        ; thing_inside }
@@ -872,12 +885,7 @@ tcRnStmt hsc_env ictxt rdr_stmt
                --     up to have tidy types
        global_ids = map globaliseAndTidy zonked_ids ;
     
-               -- Update the interactive context
-       rn_env   = ic_rn_local_env ictxt ;
-       type_env = ic_type_env ictxt ;
-
        bound_names = map idName global_ids ;
-       new_rn_env  = extendLocalRdrEnv rn_env bound_names ;
 
 {- ---------------------------------------------
    At one stage I removed any shadowed bindings from the type_env;
@@ -896,15 +904,9 @@ tcRnStmt hsc_env ictxt rdr_stmt
  
    Hence this code is commented out
 
-       shadowed = [ n | name <- bound_names,
-                        let rdr_name = mkRdrUnqual (nameOccName name),
-                        Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
-       filtered_type_env = delListFromNameEnv type_env shadowed ;
 -------------------------------------------------- -}
 
-       new_type_env = extendTypeEnvWithIds type_env global_ids ;
-       new_ic = ictxt { ic_rn_local_env = new_rn_env, 
-                        ic_type_env     = new_type_env }
+       new_ic = extendInteractiveContext ictxt global_ids emptyVarSet ;
     } ;
 
     dumpOptTcRn Opt_D_dump_tc 
@@ -1193,19 +1195,30 @@ lookup_rdr_name rdr_name = do {
     return good_names
  }
 
-tcRnRecoverDataCon :: HscEnv -> a -> IO (Maybe DataCon) 
-tcRnRecoverDataCon hsc_env a
+tcRnRecoverDataCon :: HscEnv -> Ptr () -> IO (Maybe DataCon) 
+tcRnRecoverDataCon hsc_env ptr
   = initTcPrintErrors hsc_env iNTERACTIVE $ 
-    setInteractiveContext hsc_env (hsc_IC hsc_env) $
-     do name    <- recoverDataCon a
+    setInteractiveContext hsc_env (hsc_IC hsc_env) $ do
+        name <- dataConInfoPtrToName ptr
         tcLookupDataCon name
 
 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
 tcRnLookupName hsc_env name
   = initTcPrintErrors hsc_env iNTERACTIVE $ 
     setInteractiveContext hsc_env (hsc_IC hsc_env) $
-    tcLookupGlobal name
+    tcRnLookupName' name
+
+-- To look up a name we have to look in the local environment (tcl_lcl)
+-- as well as the global environment, which is what tcLookup does. 
+-- But we also want a TyThing, so we have to convert:
 
+tcRnLookupName' :: Name -> TcRn TyThing
+tcRnLookupName' name = do
+   tcthing <- tcLookup name
+   case tcthing of
+     AGlobal thing    -> return thing
+     ATcId{tct_id=id} -> return (AnId id)
+     _ -> panic "tcRnLookupName'"
 
 tcRnGetInfo :: HscEnv
            -> Name
@@ -1229,7 +1242,7 @@ tcRnGetInfo hsc_env name
        --  in the home package all relevant modules are loaded.)
     loadUnqualIfaces ictxt
 
-    thing  <- tcLookupGlobal name
+    thing <- tcRnLookupName' name
     fixity <- lookupFixityRn name
     ispecs <- lookupInsts (icPrintUnqual ictxt) thing
     return (thing, fixity, ispecs)